What connection might there be between the conviction of Mary Queen of Scots for high treason and your own ability to use the internet in credit card transactions? There is a connection--a fairly direct one, actually. We'll bring the topic of encryption right up to date as we discuss the mathematics of secrecy, on today's Thinking Aloud with our guests, Darrin Doud and Paul Jenkins, both faculty members in the Department of Mathematics at BYU.—Original airdate: 10/21/2009